Melee Bobblehead

To get the Melee Bobblehead, one has to travel to the Dunwich Building, which is the southwestern-most structure on the Capital Wasteland. With that knowledge in mind, and with the knowledge that it's due west of Tenpenny Tower and the Warrington Trainyard, you should have no problem finding the place. It's a large structure, half-destroyed but still very much standing. Go ahead and enter the building, but be prepared to fight a slew of Ghouls during your visit, including the ever-pesky Glowing Ones.

Exploring Dunwich Building to find what you came for is going to be difficult, but it's worthwhile not only for the Bobblehead but for the immense amount of ammunition and explosives you'll find as well. You'll need to seek out a section of the building known as the Forsaken Dunwich Ruins, which will ultimately lead you to the Virulent Underchambers. Once there, the Bobblehead is below you. Drop down and follow the linear pathways and staircases. As the screenshot below, you'll find the Bobblehead lying on the ground surrounded by the debris. The good news is that the nearby door will lead you back to the regular part of the building, where escaping back to the outside world will be as easy as can be.